Clutch and brake for grinding apparatus



1952 R. E. ALLEN ETAL CLUTCH AND BRAKE FOR GRINDING APPARATUS 2SHEETSS!-1EET 1 Filed March 20, 1948 INVENTOR. ROBERT E. ALLEN WILLIAMF. UTZINGER BY MA.

A TTOR/VE Y 1952 R. E. ALLEN ETAL CLUTCH AND BRAKE FOR GRINDINGAPPARATUS 2 shuts-SHEET 2 Filed March 20, 1948 INVENTOR. TE. ALLEN uINGER so ROBER WILLIAM F BY A 77' ORA/E Y Patented Feb. 12, 1952 CLUTCHBRAKE "FOR GRINDING APPARATUS Robert Allen and William F. Utzinger,Dayton, Ohio, :assig'nors to The Univis Lens Gompany, Dayton, Ohio, :acorporation of Ohio ApplicatiomMa-rch' 20, 1948, Serial -No. usual (01.lac-.18.)

- .1 Claim.

invention relates to lens grindin :apparatus for processing lens blanks,and .more par- :ticularly to improvements in the construction ofhigh-speed lens grinders.

One of the objects of this invention is to :prowide high-speed lensgrinding apparatus having a rotating spindle for supporting a lens blankin .a grinding position, which can be :rapidly started and stopped with.a minimum of power, and which can he longitudinally displaced whilebeing driven at high speed.

Another object of the invention is to provide for an apparatus of thecharacter described a lightweight clutch mechanism for engagin anddisengaging the spindle with the power source supplying the drivingtorque.

It is also an object to provide .a braking mechanism for a high-speedgrinder of the type set vforth, the brake mechanism operatingindependently of the power source supplying the driving torque to thespindle and applying braking .power to the spindle to stop the rotationthereof rapidly.

Still another object to provide in a highspeed .lens grinder a hollowspindle adapted to :be

"rotated about .its longitudinal axis at high speed and also mounted forreciprocating motion while being rotated. the clutch mechanism operatingto engage during the entire movement of the spindle in-one direction anddisengaging when the spindle moves in the opposite direction, and .hav-

ing a brake mechanism operating to stop the rotation of the spindle whenthe clutch mechadisengages. Another :of the objects resides in theprovision of a protecting device which operates to iprevent abrasiveparticles from entering the hearing surtaces of the spindle.

Further objects and advantages of the present invention will .beapparent from the following description, reference being .had to theaccompanying drawings wherein a preferred term of embodiment of theinvention is clearly shown.

In the drawings:

1 is a front elevational view of one :form

of lens grinding apparatus, the operatinghandle being shown in theraised position;

Fig. 2 is a vertical sectional view taken on the line 2-2 of Fig. .1;and

Fig. 3 is a top elevational view, partly in sec-- tions, taken on the.line 3-3 of Fig. .1, and illustrating the operating handle in the downposition.

Referring further to the drawings, the quill housing 1.0 is formed withasubstantiallycircu-lar cross section having a central bore therein.This housing is also termed with an integral .hracket portion l8 having:a flanged edge 14 by which it can be mounted in operat ng p sition, asJoy means of the bolt and washer indicated at 15 Eig. i2 tor example.

Housing I 0 provides an outer supporting memher for the spindle sleeve:11. This-sleeve. which can be formed from a piece of steel tubing ifdesired, is reciproca'hly mounted within the housing ill as seen in Big.3. ill-he sleeve is formed with an elongated keyway is at one .sidethereof. A key I9, secured to the housing In with a cap screw2d,.is-receivedwithin this keyway toprevent the sleeve l I from rotatingrelative to the housing I ll. To provide for raising and loweringthersleeve within the housing, on the opposite side from the .keyway i8,teeth :22 are out to ,form a rack cooperating with the pinion 23. Thepinion is in turn mounted upon the shaft 2-4 and driven Soy .means ofthe ieed lever 2-5 and handle 26 in the usual manner.

The spindle 3B is rotatably mounted within the sleeve H. This spindle,which is formed with a central bore 3! extending .immend to end, seatsat its upper end within a tapered roller bearing :32 retained within theupper :end of sleeve H. At its .upper end the central bore 31 isenlarged and threaded. The tapered end of a nose piece 35 is fitted intothe enlarged bore. Nose piece :35 is also provided with a central bore,aligning with the bore 3L, .and of sufiicient diameter to receive thehollow stemmed and threaded bolt .36.

At the lower end of sleeve H, the spindle 30 is provided-with a ballbearing 40 seated against :a shoulder .formed therein. This bearing isretained in position by the nut 4| and adjusted by means of the nut-s42. With this construction, it will be readily apparent that the spindle30 is :free to rotate relative to the sleeve 1 1..

Closing the lower end of housing I0 is a pulley sleeve 45 connectedthereto by means of a set screw 46 and formed with a depending collarupon which the pulley 4Z1 ismounted. The sleeve 45 and pulley 4 1 areformed with central bores therein through which the spindle =30 extendsas shown in Fig. 2. A ball bearing 48 seats against the shoulder on thepulley sleeve collar, lacing retained in position by the U--shapedretainer ring "49. A set screw ':5l .is received through the center ofthe pulley belt groove to aid in retaining the bearing in position. Atthe upper end of the pulley a passage 52 having a pressure :type oflubrication fixture 53 fitted therein communicates with the bearing 48for the purpose of supplying a lubricant thereto. oiliseal 54 providedto, retain the vlubricant when applied under pressure. The pulley 6'! isthus mounted for free rotation relative to the sleeve 45. A drivingconnection with the spindle 30 is obtained through a clutch mechanism.

The clutch mechanism has a cup-shaped clutch drum of aluminum connectedto the bottom of the pulley 41 by means of dowels 58 and fiat-headedmachine screws 59. This drum is provided with a central aperture throughwhich the spindle passes freely. The annular side walls of the drum 5'!are tapered downwardly from the top and are adapted to engage withsimilarly tapered side walls of the clutch shoeBl.

The clutch shoe BI is also formed of aluminum and is provided with acentral sleeve portion 62 through which the spindle 3D is received. The

annular side walls of this shoe have a leather clutch facing 63 rivetedthereto. Thus when the shoe Si is moved up into the position illustratedin Fig. 2 the clutch facing 53 engages with the inner surface of theside walls of the drum 51. Since the drum 5'! is rotated by the drivenpulley 41, the shoe 6| being in engagement with the drum is also driven.When the shoe is moved down out of engagement with the drum the drivingconnection therebetween is broken.

In order to drive the spindle 30, the lower end thereof is formed with apair of oppositely disposed keyways 65 and 66. These keyways extendupward along the spindle and terminate in the shoulders 61 and 68. Theinterior of the sleeve 62 is similarly provided with keyways so that theshoe 6| can be connected thereto. A pair of oppositely disposed keys H!being received in these keyways and retained in position by means of apair of fiat-headed machine screws H for this purpose. With thisconstruction, the spindle is free to move up and down verticallyrelative to the sleeve 62 i. e., shoe 6i. It is rotated therewith,however, by means of the driving connection efiected through the keys(0.

At its lower end the sleeve 62 is slidably received within the retainersleeve 15. This sleeve, through which the spindle 30 also extends, islocked thereto by means of the key 16 and set screw 11. The coiledclutch spring 18 is retained in position by this sleeve with one endseating against the underside of the clutch shoe 6| as seen in Fig. 2.Thus when the spindle is raised the sleeve 15 moves upward relative tothe sleeve 62. Spring 18 is compressed until further upward movementcauses the shoe 6! to move up into driving engagement with the drum 51.This construction provides one of the features of this invention. Thuswhen the compression of spring 18 is properly adjusted a slight upwardmovement of the spindle will engage the clutch members 5! and BI and arapid starting of the spindle rotation is obtained. Further upwardmovement of the spindle can also be obtained where it is desired to varythe vertical movement of the spindle relative to a work piece supportedabove the upper end of the spindle for example. As will be readilyapparent from the construction disclosed, such further upward movementonly tends to compress the spring 18 to a greater extent and maintains atighter engagement between the drum 5'! and the shoe 6|. Thussubstantial vertical movement of the spindle can be obtained withouteffecting the driving engagement between the clutch members 51 and BI.

To provide for a rapid stopping of the fast rotating spindle when theclutch drum and shoe 4 are disengaged, an annular brake ring 80 is pr6-vided. This ring is mounted on a pair of brackets BI and 82 secured attheir upper ends to the housing [0 by means of cap screws. The ring issecured to the lower ends of the brackets by means of cap screws and ismaintained in spaced relation with respect to sleeve hand the lower endof the clutch shoe 6| thereby. A ring of brake lining 83 is secured tothe upper side of ring 80 by means of rivets. Thus when the clutchmembers are disengaged, the shoe 6| moves down and the lower edgethereof engages with the brake lining 83 and the rotation of the spindlestopped. It is to be noted in this construction that another of thefeatures provides for downward vertical movement of the spindle withoutdisengaging the clutch members and applying the brake until theshoulders 61 and 68 move down sufiiciently to strike the keys It. Anyfurther downward movement of the spindle disengages the clutch membersby forcing the shoe 6! away from the drum 5? and into contact with thebrake ring 39. A very rapid braking action is thereby provided whichenables the operator to wait a minimum of time only forthe spindle tostop rotating when changing operation or work pieces, for example.

To complete the assembly, this high-speed grinder is provided at itsupper end with a pan base which is mounted over the endof sleeve ll,being secured thereto with a set screw 9|. This base is formed with. acentral "opening through which the upper end of spindle 30 projects. Itis also provided with a passage 92 communicating at its inner end withthebearing 32. A fitting 93 is mounted at the outer end of this passageto provide for forcing lubrication under pressure into the bearing. Anoil seal 94 is provided to prevent the loss of lubrication along theexterior surface of the spindle at the top thereof. The pan base 98 isthus free to move vertically with the sleeve H, but does not rotate withthe spindle 36. Supported on the pan base is the water pan 96 which isformed with a central opening therein through which :the upper end ofthe spindle extends as seen in Fig. 2. This opening is of sufiicientdiameter for the pan 95 to seat down on the annular shoulder 91 formedat the top of the pan base 90. This shoulder is recessed on the interioradjacent the central bore to provide for mounting the oil seal '94.

To further protect the bearing 32 and rotating surfaces at the upper endof the spindle against the'entrance of abrasives carried in the liquidflow from the work operations performed within the water pan, a cap orflinger'lili'l is provided. This flinger is provided with a centralopening therein and is received over the upper end of the spindle, beingheld in place by means of the set screw II. The fiinger is formed withannular depending side walls [02 which extend down almost to theshoulder 91. These walls are maintained in spaced relation to providesufiicient clearance for their rotation with respect to the upwardlyprojecting shoulder 91 of the pan base 90. Since these walls overhangthe shoulder 91, which provides through the oil seal 94 the onlyentrance from the interior of the pan 96 to the bearing 32, and sincethey are rotated at a high rate of speed with the spindle 30, theytend'to fling the abrasive particles outwardly and away from the innerrotating surfaces. Such construction has been found to increase theuseful life of the machine very considerably, the machine requiring lessservicing and operating over longer periods of time under adverseconditions with fewer repairs necessary.

A stop rod I05 having a centrally positioned and elongated slot I06formed therein is threadedly connected at its upper end to the pan base90. At its lower end this rod, which is received within a bore I01formed in the projecting boss I08 in the lower part of housing I0, isprovided with a brake shoe holder I09, Fig. 1. At the upper end rod I 05is guided through the bifurcated boss IIO formed as an integral part ofthe housing I0, Fig. 3. An adjustable stop member H2 is bolted to therod I05 to provide for controlling the amount of vertical movementeffected by the sleeve II. The upper edge of the stop is adapted tostrike against the under surface of the projection IIO, while the underside of the stop in turn strikes against the upper surface of the bossI08. The movement of the sleeve I! can thus be adjustably controlled asdesired.

To further facilitate operation of the apparatus, a pulley I20 ismounted on the pinion shaft 24. A weight can be attached to this pulleyto facilitate the raising and lowering of the handle 26 and theconnected sleeve H.

In operation, a vacuum fitting can be attached to the lower end of thespindle 30 for applying suction action through the bore 3!. A vacuumtype of holder for the lens blank is then mounted and retained by thesuction action upon the nose piece 35. Then the operating handle 20 israised and lowered by the operator to bring the lens holder into and outof contact with the tool being used to' process the lens blank. Suchmovement of the handle in one direction rotates the pinion shaft 24 andpinion 23 to raise the sleeve I'I. Movement in the opposite directionreverses the rotation of shaft 24 and lowers the sleeve ii. The upwardmovement of the sleeve I! in turn raises the spindle 30, which isconnected thereto with bearings, and which permit rotation of thespindle relative to the sleeve.

To provide for the rapid starting of the spindle 30 to rotate about itslongitudinal axis, driving torque is transmitted from the pulley 41connected to a power source. This pulley is directly connected to aclutch mechanism comprising a drum 5! and a shoe 6 I. The pulley anddrum are mounted for free rotation with respect to the spindle 30. Theclutch shoe is keyed to the spindle. Thus when the drum and shoe areengaged the spindle is driven, and when these clutch members aredisengaged'driving torque is no longer transmitted to rotate thespindle.

The drum 5'! is driven constantly and the shoe BI moved into and out ofdriving engagement therewith by raising and lowering the spindle 30 asdesired. Since the spindle is free to move vertically, but notrotationally, with respect to the clutch shoe 6|, the retainer sleeve I5and spring I8 provide for vertical movement both up and down, withinpredetermined limits, while the clutch members are engaged and thespindle rotating at full speed.

In order to provide for rapid braking to stop the spindle from rotatingafter the clutch members are disengaged, a brake ring 80 is mounted inposition beneath the clutch shoe 6|. Thus when the operator causes thespindle to move down sufficiently to disengage the clutch members thelower edges of the shoe 6| come in contact with the brake ring 80 andthe rotation of the spindle is stopped.

It will be apparent from the above description that there is provided ancfiiciently operating apparatus particularly adapted for lens grindingoperations. Both rapid starting and stopping of the spindle rotation areeffected, the mass of the parts involved in these operations beingrelatively light. Thus the motor supplying the driving torque forrotating the spindle at high speed does not have to be started andstopped when it is desired to similarly control the operation of thespindle. The brake operates against only the mass of the hollow spindleand aluminum clutch shoe 6| when applied. It is also only necessary tomove these same members when the clutch members are engaged and thespindle rotated. Furthermore, when the clutch members engage to drivethe spindle, the spindle can be moved vertically upward withoutdisengaging the clutch. Also, when the spindle is moved in the oppositedirection the brake mechanism is applied to stop the rotation. There isalso provided a fiinger which prevents abrasive particles from enteringthe bearing surfaces from the upper end of the spindle.

While the forms of embodiments of the present invention as hereindisclosed constitute preferred forms, it is to be understood that otherforms might be adopted, all coming within the scope of the claim whichfollows.

We claim:

A lens grinding apparatus, in combination a spindle housing, a spindlesleeve reciprocably mounted within said housing, a spindle rotatablymounted within said sleeve, rack and pinion means connected to saidsleeve to provide for reciprocating said spindle, a pulley rotatablymounted relative to said spindle for receiving a driving torque from apower source, a clutch drum connected to said pulley and a clutch shoehaving a slidable connection with said spindle, said drum and shoe beingconstructed and arranged to move into driving engagement with respect toeach other upon longitudinal movement of the spindle in one directionand out of such .1 engagement upon similar movement of the spindle inthe opposite direction, said slidable connection providing for saidengagement of the shoe with the drum and thereafter continuedlongitudinal movement of the spindle in either direction with the shoeand drum remaining in engagement, and a brake ring positioned to engagewith said clutch shoe when the latter moves out of engagement with saidclutch drum to provide for stopping the rotation of the spindle uponlongitudinal movement thereof in said opposite direction.

ROBERT E. ALLEN.

WILLIAM F. UTZINGER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 926,184 Hart June 29, 19091,122,206 Jennings Dec. 22, 1914 1,538,506 Arnold May 19, 1925 1,569,194Long Jan. 12, 1926 2,291,629 Jackson et al Aug. 4, 1942 2,432,272 BarimDec. 9, 1947

